The term zero-day is typically used in conjunction with terms such as “vulnerability” or “exploit”.
A zero-day exploit refers to a vulnerability discovered in software for which:
“Zero-day” refers to the amount of time the software authors have to fix the issue: zero. It needs to be resolved immediately.
Any vulnerability that is first discovered by finding malware in the wild that exploits it can be considered “zero-day”.« Back to Glossary Index